Self-adjusting plier-type toggle locking wrench



June 2 1956 J. L. HOSTETTER SELF-ADJUSTING PLIER-TYPEI TOGGLE LOCKING WRENCH 2 Sheets-Sheet 1 Filed May 17, 1954 J L. Ho

June 26, 1956 J. L. HOSTETTER 2,751,801

SELF-ADJUSTING PLIER-TYPE TOGGLE. LOCKING WRENCH Filed May 17, 1954 2 Sheets-Sheet 2 Fig.4.

IN VEN TOR.

J. L. Hostetter 2,751,801 Patented June 26, 1956 Fire SELF-ADJUSTING PLIER-TYPE TOGGLE LOCKING WRENCH John L. Hostetter, Murray, Nebr.

Application May 17, 1954, Serial No. 430,241

2 Claims. (Cl. 81-84) This invention relates to tools and particularly wrenches of the plier type which are used for gripping objects, such as nuts, plates and the like, and in particular a locking wrench having compensating means therein whereby gripping jaws are automatically adjusted to grip thick objects such as nuts, or thin objects such as plates, and wherein the desired gripping force remains constant regardless of the thickness of the material or object being gripped.

One object of this invention is to provide a wrench of the plier type which is self-adjusting to all sizes of objects within its capacity range.

A further object is to provide a plier type wrench as described in which the gripping force may be readily and easily adjusted to greater or lesser power.

Another object of this invention is to provide a selfadjusting wrench of the plier type with compensating means whereby the desired pre-selected gripping force is automatically applied without special adjustment for size to all objects within the capacity range of the wrench.

A still further object is to provide a self-adjusting plier type wrench in which the desired gripping force may be pre-determined.

And a very important object of this invention is to provide a self-adjusting locking plier type wrench in which the desired gripping force is applied firmly with no possibility of slippage of the locking mechanism which otherwise might allow a gripping force to weaken and thereby cause a slipping or a letting loose of the object being held with the possibility of injury to the user.

And another object of the invention is to provide a selfadjusting locking plier type wrench in which there is a resilient means for urging a wedge used into position.

With these and other objects and advantages in view the invention embodies a stationary jaw positioned on one end of a body with the shank of the jaw extended to provide a handle, a movable jaw pivotally mounted on the shank of the stationary jaw, a handle pivotally connected to the movable jaw, toggle linkage having a locking wedge attached to one end thereof and connecting elements positioned between the handles of the jaws, a wedge adjustably mounted between the handles and positioned to coact with the toggle and the locking wedge, and a spring in the handle of the stationary jaw for urging the parts into operative positions.

Other features and advantages of the invention will appear from the following description taken in connection with the drawings, wherein:

Figure l is a side elevational view showing the locking wrench with the parts in closed positions in full lines and with the movable jaw in an open position in dotted lines.

Figure 2 is a sectional plan through the wrench taken on line 2-2 of Figure 1.

Figure 3 is a longitudinal section through the wrench taken on line 33 of Figure 2.

Figure 4 is a side elevational view similar to that shown in Figure 1 showing the movable jaw of the wrench, handle and toggle lever thereof in full lines in the open position and in dotted lines in the closed position.

Figure 5 is a cross section through the handle portion of the wrench being taken on line 55 of Figure 4.

Figure 6 is a cross section through the body of the wrench being taken on line 66 of Figure 4.

Figure 7 is a detail showing a slidable locking wedge positioned in the handle of the stationary jaw.

Figure 8 is a detail showing a perspective view of the wedge which automatically controls the positions of the aws.

Figure 9 is a plan view of the wedge.

While one embodiment of the invention is illustrated in the above referred to drawings, it is to be understood that they are merely for the purpose of illustration and that various changes in construction may be resorted to in the course of manufacture in order that the invention may be utilized to the best advantage according to circumstances which may arise, without in any way departing from the spirit and intention of the device, which is to be limited only in accordance with the appended claims. And while there is stated the primary field of utility of the invention it remains obvious that it may be employed in any other capacity wherein it may be found applicable.

In the accompanying drawings, and in the following specification, the same reference characters are used to designate the same parts and elements throughout, and in which the numeral It) refers to the invention in its entirety, numeral 12 indicating a lower or stationary jaw having a handle 14, numeral 16 an upper or movable jaw having a handle 18 which is pivotally connected thereto by a pin 20, numeral 22 a toggle connecting the handle 18 to a locking wedge 24, numeral 26 an adjustment wedge, numeral 28 a connecting link having a screw 36 for adjusting the position of the adjustment wedge, and numeral 32 a spring for urging the elements into operative positions.

As illustrated in Figure 3, the body portion of the lower jaw 12 is formed with a cavity 34 having flanges 36 and 38 at the sides providing a U-shaped section, as shown in Figure 6, and the upper jaw 16 is provided with a shank 40 by which the upper jaw is pivotally mounted in the lower jaw, the shank 40 extending into the cavity 34 and being pivotally mounted therein by a pin 42. The shank 40 is provided with a bifurcated lower end providing ears 44 on the sides of a slot 46 and an arm 48 which extends from the adjusting link 28 into the slot 46 is pivotally held in the ears by a pin 50.

The handle 18 of the upper jaw 16 is also U-shaped in cross section having flanges 52 and 54 forming side walls, and the pin 20 extends through the flanges and also through a projection 56 extended upwardly from the upper or movable jaw 16.

The toggle 22, which extends into the handle 18, as shown in Figure 3, is pivotally connected to the handle by a pin 58, and the opposite end is pivotally connected to the locking wedge 24 by a pin 60. The locking wedge 24, which is U-shaped in cross section and of a dimension complemental to and adapted to be slidably received within the cavity 34 of the handle portion 14 of the sta tionary jaw 12 and is provided with sides 62 and 64 and the upper edges 66 and 68, respectively, of the sides slope upwardly from the end in which the pin 60 is positioned to the opposite end which is indicated by the numeral 70. The sides 62 and 64 of the locking wedge 24 are also provided with cars 72 and 74, and the ears 72 and 74 are provided with projections 76 in which notches 78 are positioned and, as illustrated in Figure 3, one end of the spring 32 is held in the notches 78. The opposite end of the spring is retained under a flange 80 3 that extends from the upper edge of an end wall 82 of the handle 14.

With the parts mounted: in this manner the spring urges the locking wedge 24 and the toggle 22 toward the jaw end of the wrench and with the wedge 26 in a predetermined position the jaws are set to grip a thin or thick object with the same amount of force when the handle 18 is forced toward the handle 14. The wedge 26 is connected through the adjusting or connecting link 28 to the lower end of the shank 40 of the upper jaw by the pin 50, which is positionedbelow the pivot pin 42.

The wedge 26 is a traveling or floating element and stops when the gripping jaws 12 and 16 stop against a fixed or solid object, and by adjusting the position ofthe wedge with a nut 84 on the screw 30, the gripping force may be adjusted.

The screw 30 extends through a bore 86in the adjusting linkage 28' and the nut 84 is positioned in a slot 88 therein. The extended end. of the screw is pivotally connected to the wedge 26 by a pin 90, and, also as shown in Figure 3, the wedge is positioned between the upper edges 66 and 68 of the locking wedge 24 and a plate 92 extended across the upper edges of the sides 36 and 38 of the handle of the lower jaw.

As thus described it will be seen that theplate 92 closes the upwardly opening sides 36 and 38 of the handle 14 of the lower jaw 12 whereby a rearwardly' tapered opening is provided between the inner surface of the plate 92 and the inner surface of the handle portion 14 of the jaw 12.

The plate 92, an integral part of the stationary handle 14, ties the tops of the two sides 36 and 38 together at an angle which forms the rearwardly tapered opening in the handle in which the wedge 26 and the locking Wedge 24 coat. The inner surface of the plate 92 forms the abutment for the upper surface of the wedge 26 and the bottom or inner surface of the cavity 34 of the handle 14 forms the opposing abutment for engagement with the undersurface of the locking wedge 24. When the wedges are in contact with each other and also the respective surfaces are in contact with the respective abutment the locking Wedge 24 becomes a solid abutment for the toggle 22 through the pin 60, and locking, with a desired gripping force, may now take place.

To open the wrench the handle 18 is moved upwardly in the direction of the arrow 94, and with the wedge in the desired position, and also with a nut, plate, or the like between the jaws 12 and 16, the handles are moved together and as the parts approach the closed positions the center of the pin 58 passes over the center whereby the handles are locked with the jaws in gripping relatio with an object between the jaws.

The applicants method of self-adjustment is a simple positive action. When locked in gripping position the wrench cannotlose any of its gripping power by slippage since the two wedges 24 and 26 are being urged together within the rearwardly tapered opening of the handle 14 by the action of the movable jaw 16/ and by the toggle 22. When the wedge 26 reaches a position according to the size of the object it is engaging, then the movable jaw 16 stops moving, and a further closing movement. of the movable handle 14 now forces the toggle 22 rearward which pushes the locking wedge 24 rearward until a portion of the locking wedge 24 completely fills the space provided by the rearwardly tapered opening. At this point, the locking wedge 24 becomes a fixed abutment.

When an object of smaller size is. being gripped, the adjustment wedge 24 is moved further into the rearwardly tapered opening, the slidingabutment will become a fixed or stationary abutment for the toggle 22 with a thinner part of the locking wedge 24. Conversely, with a larger object to be gripped or held a thinner portion of the adjustment wedge 24 will enter the rearwardlytapered opening and a thicker portion of the locking wedge 24 will be required to bring the toggle abutment into afixed or stationary'position. a

It is obvious that when the point is reached where the wedges, no matter how positioned, have filled the space in the rearwardly tapered opening there, theoretically, can be no more movement of parts. But actually there may be visualized a silent further movement which actually exists and can be realized when due consideration be given to the fact that the stress or strain imposed by the wedging action causes the side walls of the rearwardly tapered opening to stretch slightly and also to compress very slightly the two wedges, various other parts and linkages bend, compress or stretch slightly as the case may be, very little, of course, but enough to allow the two wedges to-traveltogether longitudinally under the urging of both the movable jaw 16 against the adjustment wedge 26 through the adjustment link 23 and the pulling on the locking wedge 24 by the toggle 22. This slight movement, and the amount of movement will vary with the amount of gripping force desired, together with the actual distortion or springing of the handle and jaws themselves which occurs in all wrenches until a pulling strain will permit the desired gripping power to be locked onto the object andmaintained.

When the locking movement is completed, the wedges are rigidly held. Neither can move in either direction, therefore the gripping force remains constant until released by the movable handle.

Any wear such as occurs in the pivots, in the wedges and in the walls of the rearwardly tapered openingof the adjustment abutments after long use will not prevent the operation of the wrench since looseness from such wear is taken up by the adjusting nut 84.

From the foregoing specification it will become apparent that the invention disclosed will adequately accomplish the functions for which it has been designed and in an economical manner, and that its simplicity, ac curacy, and ease of operation are such as to provide a relatively inexpensive device considering what it will accomplish and that it will find an important place in the art to which it appertains when once placed on the market.

It is thought that persons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after considering the descrip tion in connection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Changes in shape, size, andrearrangement of details:

and parts, such as come within the purview of the inven tion claimed may be resorted to in actual practice, if desired.

Having now described the invention that which is claimed to be new and desired to be procured by Letters Patent, is: 7 i

1. In a wrench, the combination-of an elongated handle forming a body portion provided at one end with a stationary jaw and formed with an elongated recess, a co.-

acting movable jaw pivoted to said body, a second handle pivoted to said' movable jaw, a toggle link pivotally attached to said second handle and extending, away from said jaws and toward the farther end of said recess, a section of said handle portion which is spaced a substantial distance from said jaws being provided with a hollow portion having first and second spaced apart surfaces disposed opposite each other and extending generally linearly of said handle, said first and second surfaces each being inclinedly disposed with respect to each other and diverging away from'each other toward-the ends thereof closest the jaw end ofsaid handle, said first and second surfaces defining straight parallel 'lines extending longitudinally of said elongated handle, first and second movable wedges disposed betweensaid oppositely disposed surfaces and arranged with their wideends juxtaposed and facing the jaw end of the wrench and with their narrow ends facing the other end of the wrench, means pivotally connecting said toggle linkage to said first wedge; resilient means urging said first wedge toward said stationary jaw, said wedges being of cooperative sizes and shapes for the setting of said first and second wedges firmly between said oppositely disposed surfaces when said wrench is clamped onto an object and before said toggle link connection with said second handle reaches a point on an imaginary line between said second handlemovable jaw connection and said toggle-linkage first wedge connection, means connecting said second wedge with said movable jaw in a manner such that as said movable jaw moves toward a closed position said second wedge moves away from said stationary jaw for the above described setting.

2. The wrench described in claim 1 in which said means for connecting said second Wedge to said movable jaw is manually adjustable lengthwise of said elongated handle, whereby such adjustment controls the amount of pressure the wrench will apply to an object by determining how early in the co-action of the wedges the second wedge will set itself firmly between said oppositely disposed surfaces.

References Cited in the file of this patent UNITED STATES PATENTS 952,079 Mclntire Mar. 15, 1910 2,452,625 Alpers Nov. 2, 1948 2,487,281 Steckelberg Nov. 8, 1949 2,499,201 Thayer Feb. 28, 1950 2,531,285 Manspeaker Nov. 21, 1950 2,533,817 Koskinen Dec. 12, 1950 2,661,648 Jones Dec. 8, 1953 

